Skakel was convicted of Moxley’s murder in 2002 and sentenced to 20 years-to-life in prison. He was Moxley’s neighbor in Greenwich, Connecticut, when the 15-year-old girl was bludgeoned and stabbed to death with the shaft of a broken golf club in October 1975.

According to Skakel’s lawyer, Stephan Seeger, a golf club handle was later allegedly recovered from a residence owned by Skakel’s aunt and uncle, about seven miles from the crime scene.

Seeger says he has not located the handle in question and only recently heard claims of its existence, but he is seeking depositions to learn more. He did not specify in what way the handle might clear his client — only that it could prove the murder weapon didn’t come from the Skakels.

The club handle was allegedly discovered by a groundskeeper and his daughter. Believing it might be evidence, they brought the snapped shaft to police in Greenwich in 1999, Seeger claims.

He contends that, despite the murder conviction, Skakel was actually at his aunt and uncle’s home watching a Monty Python movie with a cousin on the night Moxley was killed.

Seeger says a Connecticut-based lawyer contacted him late last year about the alleged golf club shaft’s existence. The unnamed lawyer also provided him with the names of the groundskeeper, his daughter and a lawyer who once worked for Skakel’s aunt and uncle.

Seeger says the groundskeeper passed away on March 31, at 91, but he still wants to depose the daughter as well as the former attorney for the aunt and uncle.

Seeger has asked Superior Court Judge Gary White to issue subpoenas for these people to provide depositions on the matter, PEOPLE confirms. He says he wants as much information on the alleged golf club handle as possible.

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Martha Moxley

AP Photo

“We are trying to find this missing evidence,” says Seeger, who insists there isn’t even an official police report reflecting the groundskeeper’s visit to police in Greenwich.

Neither investigators nor Skakel’s cousin’s family immediately returned PEOPLE’s messages seeking comment; the other parties Seeger identified could not immediately be reached.

But “even the greenest of police officers in 1999 would have found the report of a golf club shaft being found at the [aunt and uncle’s] residence to be ultra significant,” Seeger argues. “That item should have been inventoried right away — and at a minimum, there should be a police report saying two people came in with this item, when they found it and where.”

“There are mountains of documents associated with this case and not one sentence written about this golf club handle,” Seeger continues. “That is exceptionally odd.”

Speaking to PEOPLE last year, Moxley’s mother said she still thought Skakel was guilty: “I believe Michael is the one who swung the club. It has been 41 years since Martha died. When you gather all this information for that long a time, you get to a point where you put it all together and it just fits.”

Skakel spent 11 years behind bars after his conviction. Today, he is living with a relative in Bedford, New York.

Seeger tells PEOPLE he isn’t pointing fingers about the new claims over the golf club handle.

“My hope is always that there has been an oversight and that justice can be served in light of this new evidence,” he says. “It doesn’t take a genius to put the pieces of the puzzle together.”